Dojima has short, grayish black hair, gray eyes, three-day stubble, and broad shoulders. He is frequently seen wearing a dark gray shirt with pulled up sleeves, a loose, light red necktie and a brown belt with a metal buckle as well as a pair of dress pants along with dark brown shoes. On his left arm, he has a silver wristwatch. Despite carrying it around most of the time, Dojima is never seen wearing his black jacket.

In Persona 4 The Animation, Dojima occasionally carries a pack of cigarettes in his shirt pocket.

Living alone with his daughter, Dojima is shown to be a hard working detective, although he often becomes a workaholic. While he cares about his daughter, he has severe problems in being a father for her as she constantly reminds him of his deceased wife, Chisato. In addition, his line of work means that he's almost always busy, and he leaves Nanako alone in the house for long periods of times (even during the Inaba serial killer case), something which later leads to her kidnapping.

According to the events of his Social Link, Dojima did not understand the true meaning of "family" until the protagonist arrived, further pointing out the familial problems of the Dojimas. He is also worried about the protagonist's involvement in the case, and gets easily enraged when stressed.

Dojima is the father of Nanako Dojima and the protagonist's uncle from his mother's side. Dojima works as a police detective in Yasoinaba, and is helped by his assistant Tohru Adachi. He lives at the Dojima Residence east of Inaba. Dojima lives alone with his daughter until the protagonist temporarily stays with them. His Arcana is the Hierophant, so increasing his Social Link empowers the player's Hierophant Personas.

A photo of the Dojima family with Dojima, Nanako and Chisato.

A detective of the Inaba police force, Dojima personally handled the mysterious serial killings. At the same time, his Social Link reveals that he was also pursuing an older case regarding a hit and run that killed his wife years ago. Because of this, he is often away from home, and comes home late, leaving his young daughter Nanako to look after herself. Throughout the game, Dojima shows concern that the protagonist is involved in the case, and often scolds him for supposedly putting his life in the line for such matters.

Later in the game, on November 5, Dojima intercepts a threatening letter sent to his house addressed to the protagonist. Convinced that the protagonist is involved in the serial murder case in some way, Dojima detains him at the police station for questioning, leaving Nanako at the house alone. The protagonist reveals the truth that he goes inside another world and uses a special power known as Persona, but Dojima doesn't believe this and dismisses it as a fantasy. He leaves the protagonist to remain in the room for the night.

Dojima begging his nephew and Naoto to save Nanako.

Matters take a turn for the worse when that same night, Nanako is kidnapped and the Investigation Team takes action. Upon learning that Nanako's kidnapper is in fact Taro Namatame, Dojima heads into his car and gives chase. However, Namatame abruptly stops his car and turns, causing Dojima's car to crash. Dojima ends up sustaining heavy injury, and is taken to the hospital. He entrusts the protagonist and Naoto Shirogane with rescuing Nanako, knowing inherently that he has the ability to do so. Later, both Nanako and Namatame are admitted to the hospital. It is stated that Dojima would often storm out of his hospital room to visit Nanako and at other times interrogate Namatame.

On December 3, Nanako's condition suddenly worsens, and before Dojima can see her, she seemingly passes away. It isn't until Nanako is on her deathbed that he realizes how much she means to him, and he regrets not being a better father and caring for her more. He storms off to Namatame's room to kill him, but is taken away by Adachi and two other officers guarding the room. The Investigation Team arrives shortly after and confronts Namatame, and what happens afterwards depends on the protagonist's decision.

In the Bad Ending, Namatame is thrown inside the television, while Nanako is confirmed dead. Dojima is released from the hospital, and the game fast forwards to the day the protagonist leaves Inaba. Dojima grieves over Nanako's death, and says he will be lonely from then on as he will be all by himself in his house. He takes the protagonist to the station for his departure, but before doing so, he subtly implies that he is aware that the protagonist punished and murdered Namatame and is thankful to him for it.

In the Neutral Ending, Namatame is spared, but the true killer is never identified. Nanako lives but remains hospitalized. On the day the protagonist leaves Inaba, Dojima laments that Nanako couldn't make it out of the hospital in time to say goodbye to the protagonist, and that she could've come out if a little more time had passed. He reveals that he cannot do anything more for the case other than testify in court, and doesn't see Namatame getting a very harsh sentence. Before taking the protagonist to the station, Dojima asks him if he is satisfied with his time in Inaba, and the choices he made. Alternately, if Namatame was interrogated prior to this ending, Dojima will reveal that though Namatame was responsible for Nanako's condition, he questions if Namatame was truly responsible for the first two murders.

In the Good Ending, Dojima continues to interrogate Namatame. When the Investigation Team continues investigation, they discover that Dojima's assistant, Tohru Adachi, has strong evidence of being the killer. That same night, Adachi relocates Namatame, against Dojima's orders, as Dojima still needed to interrogate him more. The Investigation Team arrives and questions Adachi about details regarding the first two murders and the warning letters. Both Dojima and the Investigation Team become suspicious of Adachi when he accidentally blurts out the true method behind the murders (pushing people inside televisions). After he is cornered, Adachi flees into the television as escape. While the Investigation Team gives chase, Dojima calls security. He goes to the team and reveals that according to security, Adachi has not left Namatame's hospital ward and is still in that location somewhere, only to be informed that Adachi is nowhere to be found. The nurse find Dojima and takes him back to his room for his rest. Before he leaves, he entrusts the Investigation Team with tracking down Adachi. It is implied that he later declared Adachi a wanted suspect for the murders of Mayumi Yamano and Saki Konishi.

Once Adachi is captured by the Investigation Team, Dojima sends his fellow officers to Junes to take Adachi into custody. He reveals that he cares about Adachi as an assistant, and does him a personal favor by preparing an ambulance to take Adachi in.

Dojima is released from the hospital on December 25 along with Nanako, who has fully recovered. The Investigation Team throws a Christmas party for Nanako at Dojima's house. While the party goes on, Dojima reveals to everyone that Adachi confessed to his crimes, and that he will most likely face punishment for his actions.

Dojima says goodbye to his nephew.

The day the protagonist leaves Inaba, Dojima bids him farewell along with Nanako and the Investigation Team. He reveals that the police are having an easy time building a case against Adachi due to the fact that he fully confessed to his crimes.

In the new epilogue of Persona 4 Golden following the True Ending, Dojima is asked by the protagonist's friends to join them in their surprise party for him. Dojima pretends that he is busy and not at home when the protagonist attempts to contact him. Once the surprise party ends, Dojima invites the protagonist and his friends to a large meal that he prepared for the protagonist's return. He comments on how Inaba has become more lively since the incidents ended and the fog lifted. He reveals that Namatame was released on lack of evidence, and that he apologized to Dojima himself, who told him that he should find his own way to make up for it. Namatame later revealed that he was going to run for mayor. Dojima then states that he visited Adachi, who was successfully indicted as his testimonies included statements that only the real killer could know. Adachi also claimed that he receives better treatment behind bars than he did when he was working with Dojima. Later, Dojima also reveals that he is making more progress on the case regarding his wife's death, and is grateful to the protagonist for helping him draw the line between work and family.

Going through the S.Link, Dojima and the protagonist bond through idle chatter about their lives at the dining table. Over the course of the story, Dojima then admits to the protagonist the fate of his wife-- she was killed in a hit-and-run while on her way to pick Nanako up from school. Ever since then, Dojima had been fervently searching for information to find the culprit, in hopes of avenging his wife's death and perhaps, ending his sorrows as well. This however, as shown in the later events of his Social Link, seems to be an excuse to avoid spending time with Nanako, who reminds Dojima of his wife too much.

Knowing it was probably a sedan made overseas that killed her, Dojima admits that the culprit has most likely already left the country. Dojima then confides into the Protagonist of his hopelessness at the situation, as he feels that he may just have to swallow his misery without being able to move on in life. This inner conflict is later on settled when Nanako attempts to run away from home, that Dojima realizes his role as a father, and reexamines his choices to live his life: to simply keep running away from reality, or to face the truth head-on and advance in life.

At the end of the S.Link, Dojima realizes that Nanako and the protagonist are his family, and that he needs to care for them more than his work. They celebrate the day they "officially" became a family with a cake. Dojima then gives the protagonist his very own personal Coffee Mug for him to drink with, as he "makes a fantastic cup of coffee, [if he says so himself]." Dojima admits to the MC that the mug that he was using before belonged to his late wife.

Dojima takes Nanako with him to visit the city during the events of the game, where the two meet Kanami Mashita. At the TakuraPro Dojima restrains a suspicious man who wanted Kanami's blood thinking the curse video would kill him.

Arc System Works originally wanted Ryotaro Dojima as one of the playable characters of Persona 4 Arena during the pre-planning stages when they were deciding on the cast. Takumi Iguchiya joked that instead of a Persona, he would summon Nanako Dojima to his aid. However, Atlus rejected that concept.

According to Persona 4 Game Drama CD Vol. 2, Dojima's favorite food is Gyōza, which are dough dumplings, usually filled with cabbage and minced chicken or pork, optionally in combination with sesame oil and garlic.